Electrolytic process of producing diacetone-keto-gulonic acid



Patented July 3, 1 951 UNITED STATES PATENT OFFICE ELECTROLYTIC PROCESS OF PRODUCING DIACETONE-KETO-GULONIC ACID Albert Verheyden, St. Denijs-Westrem, Belgium This invention relates to the production of diacetone-keto-gulonic acid and it is an object thereof to prepare diacetone-keto-gulonic acid by electro-chemical oxidation of sorbose diacetone in alkaline solution, in the presence of an oxygen carrier.

The oxidation of sorbose diacetone into diacetone-keto-gulonic acid is at present effected chemically, chiefly by means of potassium permanganate.

As compared with this method, the electrochemical process should have e. g. the advantage of a reduced consumption of reagents, but it has not been carried out on account of difiiculties due to the violence of ,the anodic oxygen, which frequently produces a too far reachin oxidation of the organic matter.

In accordance with the present invention, I avoid these difficulties in carrying out the electrochemical oxidation of sorbose diacetone in alkaline solution, in the presence of an oxygen carrier, by introducing the sorbose diacetone into the electrolyte gradually in proportion to the regeneration of the oxygen carrier by the electric current. By operating in this manner I avoid the degradation of the oxygen carrier to a lower oxidation stage which would not be directly regenerable by the electric current. Favorable yields are thus obtained with small quantities of oxygen carrier.

In carrying out the oxidation of sorbose diacetone into diacetone-keto-gulonic acid, the process according to this invention makes it possible to reach a yield of 70 to 85%.

As oxygen carriers, there may be mentioned for instance soluble per-salts, bichromates and permanganates. The following example is not limited in this respect.

Ewample In an electrolysis vat provided with an anode of non-oxidable steel, an iron cathode and a stirring device, I place 400 cubic centimeters of electrolyte containing KOH and 0.8% KMllO'i. After having brought the current to an anodic density of l a. per square decimeter and a cathodic density of 40 a. per square decimeter, I gradually add 18 grams of sorbose diacetone either in the solid state or in liquid solution. During the electrolysis, the temperature of the solution is kept between and 20 C. The addition of sorbose diacetone is regulated so that it is completed shortly before the consumption has reached ampere-hours. The electrolysis is then stopped and the diacetone-keto-gulonic acid is separated 6 Claims. (Cl. 204-79) from the electrolyte by known methods. The yield is over The consumption of permanganate amounts to only 3.5 parts for 18 parts of sorbose diacetone.

As indicated in the above example, the quantity of oxygen carrier utilized is substantially below and preferably approximately one fourth the stoichiometric quantity required for oxidizing the sorbose diacetone to diacetone-keto-kulonic acid.

I claim:

1. In a process of producin diacetone-ketcgulonic acid, subjecting sorbose diacetone in aqueous alkaline solution to electrolysis Without application of heat in the presence of a quantity of oxygen carrier effective in an alkaline medium to oxidize said sorbose diacetone, said quantity being substantially lower than the stoichiometric quantity required for oxidizing said sorbose diacetone to diacetone-keto-gulonic acid, and gradually feeding sorbose diacetone into said solution as the oxygen carrier is being regenerated in situ by the electric current.

2. In a process of producing diacetone-ketogulonic acid, subjecting sorbose diacetone in aqueous alkaline solution to electrolytic oxidation without application of heat and in the presence of an oxygen carrier effective in an alkaline medium to oxidize said sorbose diacetone, the quantity of said oxygen carrier being about onefourth of the stoichiometric quantity required for oxidizing said sorbose diacetone to diacetone-ketcgulonic acid, and gradually feeding sorbose diacetone into said solution at a rate in proportion to the regeneration in situ of said oxygen carrier by the electric current.

3. In a process of producing diacetone-ketogulonic acid, subjecting a portion of sorbose diacetone in alkaline solution to electrolysis in the presence of soluble permanganate, the quantity of permanganate being approximately one-fourth the stoichiometric quantity required for oxidizing said sorbose diaceton to diacetone-keto-gulonic acid, and gradually feedin further portions of sorbose diacetone into said solution at a rate in proportion to the regeneration in situ of said permanganate by the electric current.

4. In a process of producing diacetone-ketogulonic acid, subjecting sorbose diacetone in an aqueous alkaline solution to electrolysis employing a current of an anodic density of 4 amperes per square decimeter and a cathodic density of 40 amperes per square decimeter, in the absence of heat supplied from an external source and in the presence of an oxygen carrier effective in an alkaline medium to oxidize said sorbose diacetone,

density of 40 amperes per square decimeter, in

the presence of an oxygen carrier eifective in an alkaline medium to oxidize said sorbose diacetone and in the absence of heat supplied from an ex ternal source, the quantity of oxygen carrier being substantially lower than the stoichiometric quantity required for oxidizing said sorbose diacetone .1

to diacetone-keto-gulonic acid, and gradually feeding sorbose diacetone into said solution at a rate in proportion to the regeneration in situ of said oxygen carrier by the electric current.

6. In a process of producing diacetone-ketogulom'c acid, subjecting a portion of sorbose diacetone in aqueous alkaline solution to electrolysis employing a current of an anodic density of 4 amperes per square decimeter and a cathodic 2559,03 1 -T g l 4 density of 40 amperes per square decimeter, in the presence of soluble permanganate, the quantity of said permanganate being approximately one-fourth of the stoichiometric quantity required for oxidizing said sorbose diacetone to diacetoneketo-gulonic acid, and gradually feeding further portions of sorbose diacetone into said solution at a rate in proportion to the regeneration in situ of said permanganate by the electric current.

ALBERT VERHEYDEN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,084,641 Haller June 22, 1937 2,301,811 Reichstein Nov. 10, 1942 2,357,251 Weijlardet a1 June 16, 1945 OTHER REFERENCES Ser. No. 203,242, Gottesmann et al. (A. P. C.), published June 15, 1943.

Glasstone et al.: Electrolytic Oxidation and Reduction (1936), pp. 339-341.

Chemical Abstracts, vol. 40 (1946), p. 5447 (U. S. S. R. patent, 64,479, Apr. 30, 1945). 

1. IN A PROCESS OF PRODUCING DIACETONE-KETOGULONIC ACID, SUBJECTING SORBOSE DIACETONE IN AQUEOUS ALKALINE SOLUTION TO ELECTROLYSIS WITHOUT APPLICATION OF HEAT IN THE PRESENCE OF A QUANTITY OF OXYGEN CARRIER EFFECTIVE IN AN ALKALINE MEDIUM TO OXIDIZE SAID SORBOSE DIACETONE, SAID QUANTITY BEING SUBSTANTIALLY LOWER THAN THE STOICHIOMETRIC QUANTITY REQUIRED FOR OXIDIZING SAID SORBOSE DIACETONE TO DIACETONE-KETO-GULONIC ACID, AND GRADUALLY FEEDING SORBOSE DIACETONE INTO SAID SOLUTION AS THE OXYGEN CARRIER IS BEING REGENERATED IN SITU BY THE ELECTRIC CURRENT. 